Variable resistance



Patented May 9, 1922.

RNEYS.

INVENTOR Harold P, Dayle H. F. UONLE.

VARIABLE RESISTANCE.

APPLICATION FILED DEC. 15, 1921.

UNITED. STATES.

PATENT OFFICE.

HAROLD POTTER DONLE, OE MERIEEN, CONNECTICUT, AssIGNOR TO THE CO NECTIC T TELEPHONE & ELECTRIC COMPANY, INCORPORATED, OE MERI- DEN, CONNECTICUT, A CORPORATION OF CONNECTICUT.

VARIABLE RESISTANCE,

Specification of Letters Patent. 7

Application filed December 15, 1921. Serial No. 522,460.

To'all whom it may concern:

Be it known thatI, HAROLD P. DONLE, a citizen of the United States of America, residing at Meriden, Connecticut. have invented a new and useful Variable Resistance, of which the following is a specification.

' The main object of my invention is to provide a simple, compact structure having two independently adjustable coils.

Another object is to so construct such a device that it may be readily mounted behind a panel board but be readily operated from the front of the board.

Another object is to facilitate the con struction, assembly and adjustment of a resistance device suitable particularly for radio work.

In the preferred form of my invention, as illustrated inthe accompanying drawings,- I mount two coils on an insulating block, the coils being disposed at the front and rear of the block, respectively. Each coil is provided with a rotatable contact arm and a knob for operating the same. .The coils and knobs have a common axis, and the shaft of one knob passes longitudinally through the hollow shaft of the other knob.

Figure 1 is a front view of a construction embodying the improvements of my inven tion;

Fig. 2- is a longitudinal sectional view of the same, showing the construction mounted On a panel board or support;

.Fig. 3 is a perspective view showing various parts of the device disassembled; and Fig. 4 is a diagramshowing one-circuit arrangement in which the device may be used.

The insulating block or body 5 maybe formed of any suitable material, such as molded composition. The wire of the coils 6 and 7 is wound on insulating strips adapted to fit the front and i'ear-ends,respectively, of the insulating block on Opposite sides of the flange 8. -Each coil strip is provided with terminal pieces, such as 9 and 10, which are adapted to be anchored to the insulating block in a suitable manner, as, for instance, by means of rivets lland '12 which are embedded in the insulating block.

A tubular member 13 is mounted in the insulating block and secured in place by having its rear end spun overor upset behind the washer 14.

On the front of the block 5 I mount a conducting terminal 15, which may be s ecured by one or more rivets, such as 16, embedded in the block.

Upon the sleeve 13 I mount a contact member 17, having a hub 18. This contact member effects electrical connection between the terminal plate 15 and the coil 6. The

Patented May 9, 1922.-

. The Contact member 20 for the coil 7 has a hub 21, which issuitably secured on the rear end of the central shaft 22. An in-- sulating operating knob 23 is provided for insulating bushing 24, which fits in the sleeve 13 and in the rear terminal plate 25. A spring washer 26 may be provided to frictionally hold the parts in position.

The terminal members 9 and 10 serve as stops to limit'the rotative movement of the front contact arm 17, and the terminal pieces 27 and 28 Ofthe rear coil 7 serve as stops to limit the movement ofthe rear Contact arm 20. In the form shown the two terminal pieces 9 and 27 are electrically connected by a link 29.

The method of assembling and separating the parts will be readily understood from .the foregoing description of the construction.

The construction may be supported on a standard, or panel 30, as indicated in Fig. 2. For this purpose screws, such as 31, are provided, which are adapted to pass through a spacer 32 and screw into the. eyelets or studs 16, which also secure the terminal plate 15 tothe insulating block 5. The member 32 the resistance of each coil is adjustable independently of the other coil.

I claim: 1. A resistance device of the character described, comprising an insulating body, resistance coils mounted on the front and rear thereof, adjustable contact arms for said coils, and operating knobs for such contactarms having. a common axis.

2. A resistance device comprising an insulating block, resistance coils on the front and rear thereof, ahollow sleeve secured to said block, a contact arm rotatabl mounted on said sleeve for co-acting with one coil. a rotatable shaft extending through said sleeve,-and a contact arm carried by said sha-ftfor co-acting with the other coil.

3. In a device of the character described, an insulating block, resistance coils onthe front and rear thereof. an insulating fla'nge between said coils, and independently adjustable contact. arms for said coils.

4. In a device of the character described. an insulating block, circular coils mounted onthe front and rear thereof, terminal pieces for each coil secured to said block. and independently rotatable contact arms for said. coils. said terminal pieces serving as stops to limit the movement of said arms.

5. In a device of the character described. an insulating block. a circular coil having a core embracing said block with its ends secured thereto, a sleeve having one end upset in said block.a terminal plate secured to said block about said sleeve. a contact arm having a hub rotatably mounted on said sleeve in contact with said plate. and an insulating operating knob 'rotatablv mounted on said sleeve and. having a tongue and groove connection with said hub.

6.-In a device of the character described,

an insulating block, coils-mounted on the I knob for the front endof said shaft, and acontact arm secured to the rear end of said shaft to co-operate with the coil at the rear of said block. I

T. In a device of the character described. an insulating block. coils mounted on the front and rear thereof. a panel plate secured at the rear of said block.'a terminal plate secured tothe front of said block, and independently adjustable contact arms rotat abl v mounted in contact with said plates.

8. In aresistance device, a block coils and central terminal plates on opposite ends thereof. contact arms rotatively mounted with respect to said plates. and coaxial operating knobs for said arms.

9. In a resistance device. a block. coils thereof, cdntact armsjrotatively mounted with respect to said plates. an operating knob for one arm, and a shaft extending through said knob to operate the other arm.

10. A resistance device comprising a block. coils on opposite sides thereof, independent contact arms co-acting with, said coils. and separate operating knobs detachablv connected with said arms.

11. In a. resistance device. an insulating block having a passage. a sleeve supported therein, a rotatable contact arm and operating knob'on said sleeve. a shaft extending through said sleeve, and a. contact arm and knob on said shaft.

12. In a. resistance devicqan insulating block. rotatable contact arms on opposite ends thereof, and co-axiallv mounted oper ating knobs for said arms.

13. In a resistance device. a block. a coil carried thereby, asleeve mounted in said block, an insulating bushing in said sleeve] a contact arm, and an operating shaft therefor supported in said bushing.

HAROLD POTTER DONLE.

and central terminal plates on opposite ends 

